A bias in the "mass-normalized" DTT response - an effect of non-linear concentration-response curves for copper and manganese.

ABSTRACT: The dithiothreitol (DTT) assay is widely used to measure the oxidative potential of particulate matter. Results are typically presented in mass-normalized units (e.g., pmols DTT lost per minute per microgram PM) to allow for comparison among samples. Use of this unit assumes that the mass-normalized DTT response is constant and independent of the mass concentration of PM added to the DTT assay. However, based on previous work that identified non-linear DTT responses for copper and manganese, this basic assumption (that the mass-normalized DTT response is independent of the concentration of PM added to the assay) should not be true for samples where Cu and Mn contribute significantly to the DTT signal. To test this we measured the DTT response at multiple PM concentrations for eight ambient

SUBMITTER: Charrier JG 

PROVIDER: S-EPMC5031483 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature